MARSUPIALIA. 123 
The matrix of the animals of this family does not open by a 
single orifice into the extreme end of the vagina, but commu- 
nicates with this canal by two lateral tubes resembling handles. 
The premature birth of the young appears to depend upon 
this singular organization. The scrotum of the male, contrary 
to what obtains in other quadrupeds, hangs before the penis, 
which, when at rest, is directed backwards. 
Another peculiarity of the Marsupialia is, that notwithstand- 
ing a general resemblance of the species to each other, so stri- 
king, that for a long time they were considered as one genus, 
they differ so much in the teeth, the organs of digestion and 
the feet, that if we rigorously adhered to these characters, we 
should be compelled to separate them into several orders. 
They carry us by insensible gradations from the Carnaria to 
the Rodentia, and there are even some animals which have the 
pelvis furnished with similar bones;, but which, from the want 
of incisors or of all kinds of teeth, have been approximated to 
the Edentata, where, in fact, we shall leave them, under the 
name of Monotremata. 
In a word, we would say that the Marsupialia form a dis- 
tinct class, parallel to that of Quadrupeds, and divisible 
into similar orders: so that if we were to arrange these two 
classes into two columns ; the Sarigues, the Dasyuri, and the 
Perameles would be opposite to the insectivorous Carnaria 
with long canini, such as the Tenrecs and the Moles; the Pha- 
langers and the Potoroos, opposite to the Hedge-hogs and 
Shrews; the Kanguroo, properly so called, cannot be com- 
pared with any thing; but the Phascolomys should be opposite 
to the Rodentia. Finally, if we were to consider the bones 
of the pouch only, and regard as Marsupialia all the animals 
that possess them, the Ornithorinci and the Echidne would 
form a group parallel to that of the Edentata. 
_ Linneus arranged all the species he was acquainted with 
under his genus Didelphis, a word signifying double uterus. 
The pouch in some respects is in fact a second one. 
The first subdivision of the Marsupialia is marked by long 
canini, and small incisors in both jaws, back molars bristled 
with points, and all the characters in general of the insecti- 
Oty 
